Fix mail sent from localhost generates wrong AAR stamp

[markeissler]

When a message is constructed locally (for local or external delivery), the following happens:

• No arc Authentication-Results stamp is added to the message
• The AAR looks like this: ARC-Authentication-Results: i=1; lists.arctest.net; none Expected: AAR: i=1; lists.arctest.net; arc=none smtp.client-ip=127.0.0.1